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ExxonMobil Chemical Plant (286), Baton Rouge

Releases of Hydrogen Sulfide

LDEQ Accident Number
Accident Date
Point Source(s) Notes Amount of Release

H furnace

Cause: Three events occurred within 24 hours of one another at the ExxonMobil Baton Rouge Chemical Plant. Two are reported in this report (LDEQ #107433), the other is reported separately (LDEQ #107421). In this incident (107433), a furnace tube leaked into convection section of H-furnace and caught fire. The tube leak occurred as a result of the incident described in report #107421. At approximately 5:56 PM on July 21, 2008, the charge gas compressor at the Olefins unit shut down when several processing cards in the gas turbine control system failed. When the compressor shut down, four furnaces automatically shut down and the gas in the furnaces was evacuated to the flare system. One of the remaining three furnaces was subsequently shut down while the remaining two furnaces continued to operated at 50% rates in order to maintain stable unit operations, which resulted in additional flaring for the duration of the event. The high rate of gas to the flare system resulted in the #25 flare smoking for 2 hours and 17 minutes. When the Olefins unit shut down, steam was introduced into the furnaces to displace the hydrocarbon feed to reduce flaring emissions. At 12:20 PM on July 22, 2008, while the H furnace was in the process of starting up, a leak was discovered in the convection section of the furnace. To stop the leak, water was introduced into the leaking pass of the furnace to displace the hydrocarbon feed. It is believed that the leak developed when steam was introduced into the furnace. Tube leaked into convection section of H-furnace and caught fire.

Followup: Yes

Notes: This incident is the result of the incident #107421 (see comments under that incident). Immediately after the incident began, five of the seven furnaces at the Olefins unit were shut down. Excess gas was sent to flare system. Water was introduced into the leaking furnace pass to displace the feed and prevent uncombusted hydrocarbons from leaking into the atmosphere. Concerning subsequent preventative actions, the failed processing cards were replaced. The H furnace was taken out of service to be inspected for leak location and repairs will be completed as necessary. Used water in the tube to eliminate the burning material. Flammable gass consisted of mainly Butane.

vent on knockout drum
Cause: Experienced a vent opening on a knockout drum.

Followup: no

Notes: No additional information given.
267.5 pounds

SACC unit LTO1
Cause: A leak developed in a fifty four inch overhead pipe at the SACC Unit LT01.

Followup: No

Notes: There is approximately 5 lbs per square inch (psi) or pressure on the pipe. The insulation of the pipe was removed to identify the source. Pictures included of the plug of the pipeline due to the hole and a view of the repaired line. On the incident report form it says that the initial report said that RQs might be exceeded, but that none were exceeded.

No Information Given
Cause: Caused by a loss of power.

Followup: No

Notes: Release was being consumed in a furnace. No other information available at time of report. Amount of hydrogen sulfide released was unknown.

No Information Given
Cause: Caused by a loss of power.

Followup: No

Notes: Release was being consumed in a furnace. No other information available at time of report. Amount of hydrogen sulfide released was unknown.

Thermal oxidizer F5
Cause: Thermal oxidizer F5 tripped because of water supply being lost to it. They had a mechanical problem with the pump.

Followup: No

Notes: Called because the release was ongoing at the time and close to reaching 100 lbs (reportable quantity). They had mechanical problems with the pump and were repairing them.
83.0 pounds

Pipe on thermal oxidizer
Cause: Hole in a pipe on a thermal oxidizer

Followup: No

Notes: According to the Plant's Environmental Manager, a hole developed in a pipe on a thermal oxidizer releasing flammable gas and sulfur dioxide into the atmosphere. Operators quickly shut in the unit. Further action by LDEQ pening results of investigation. Quantities of released chemicals are estimates.
100.0 pounds

No Information Given
Cause: E-201 exchanger had leak. Estimated releases were >10lbs of Benzene and >100lbs of Hydrogen sulfide

Followup: No

Notes: Just the written letter. It says that after further evaluation, it was determined that no RQs were exceeded.

stripper tower
EPLA-W compressor
Cause: The EPLA-West compressor trip also caused the liquid to be sent to the hydrogen compressor at the benzene hydrotreater unit (BHLA). This led to the trip of the hydrogen compressor and shut down of the BHLA unit. This unexpected shut down caused the overpressure of the stripper tower above the PSV setting

Followup: No

Notes: This incident is linked to incident #112825, which is when the safety valve on the tower blew. The benzene release to air was above RQ limit.
100.0 pounds

EPLA-W Compressor, flares #10, 25, and 26
Flares #10, 25, and 26
Cause: A fire resulted in a compressor shut down and material being flared from 10:30 pm - 11 pm. Around 10:30 pm the charge gas compressor (EPLA-W compressor) for the Olefins Maintrain furnaces tripped due to failed overspeed wiring. This occurred because of a small leak of lube oil from the steam driver which caught fire. This fire was small but close to the wiring which malfunctioned.

Followup: No

Notes: This incident is linked to incident #112824. The effluent gases were diverted to flares before the compressor could be repaired. Start up began around 8:45 pm on 2/18/09. Flaring during shut down through start up resulted in exceedances of RQs for ethylene, propylene, butadiene, nitric oxide, and sulfur dioxide. Also they had three compliance excursions from smoking of flares #10, #25, and #26. This was a non preventable incident from a malfunction. They are looking into preventing lube oil leaking and collecting near compressor wiring.
12.0 pounds


Cause: A compressor tripped offline at the Benzene Hydro-Finer and caused the automatic shut down procedure to be activated.

Followup: No

Notes: The release resulted in a temporary localized shelter in place.

Knock-out drum D-28
Cause: Vent on a drum popped open. Root cause was high liquid level in the drum and vent valve relieved as per design.


Notes: During normal operations, the acid gas is incinerated at furnaces F-5 and F-6. Before going to the incinerators, the liquid is removed from the steam at a knock out drum, D-28. The cause of the high liquid level is under investigation. Upon completion of this investigation, this event will be reviewed with all operating personnel and investigation recommendations will be tracked and steqarded to ensure completion. SPOC report said 126 of hydrogen sulfide were released, Exxon's report says 76.3 lbs were released. The D-28 liquid level was drained, per procedure, which allowed the vent valve to re-set in the closed position.
76.3 pounds

compressor KC-01
Cause: A combination release occurred due to a cracked pipe in the thermo well of the ethylene production unit.

Followup: Yes

Notes: An engineered clamp is being fabricated and will be installed to isolate the leak. Estimated 72 hours to install clamp and secure leak. Individually this event did not exceed the RQ for HRVOC, but in combination with another incident (#11-07037) the RQ for HRVOC was exceeded on Friday, November 11. Approximately 122 pounds of HRVOC's were released. On November 11, 2011 at approximately 13:51 Derek Reese stated the ongoing release subsided to 4.25 lbs/hr and was now below RQ. (still ongoing on report date 11/16/11) Area monitoring and LDEQ monitoring on the fenceline (including grab sample) did not detect anything. LDEQ did pick up .25ppb of Benzene. A total of 108 pounds per day of charge gas is being released as a result of this event. Cumulative emissions which include the total emissions from the incident and complete response, will be included in the follow-up report.
24.0 pounds

Cause: There was a leak on a BHLA Unit. An unknown liquid is coming from the unit.

Followup: No

Notes: A shelter was in place for that area and the shelter was confined to the plant. Based on a total release of 10 gallons of water, as well as the solubility of hydrogen sulfide in water, less than one pound of hydrogen sulfide was released.

Flare gas system
Cause: A failure of the fuel gas control valve servomechanism actuator failed due to particulate matter in the hydraulic system, causing OLA-2X gas turbine to trip and material to be released to the Site's flare gas system.

Followup: Yes

Notes: Feed was removed from five of seven furnaces and the remaining two furnaces were operating at minimal rates in order to reduce the load on the flare system and emissions to the atmosphere. The hydraulic oil filters and servos were replaced upon discovery of the foulant. The hydraulic oil system was drained, cleaned, and charged with fresh oil in December 2012 to remove a suspected contaminate and particulates. ExxonMobil is conducting additional laboratory analysis of the lube oil at our lubes and specialities lab to determine if additional steps are needed to help prevent recurrence. In addition, improved filtration has been installed. A citizen complaint was recorded and given LDEQ incident number 144543. The complaint cites "Exxon release causing terrible odors, making the caller sick." The LDEQ report references this report, incident 144539 for information on the release. The reportable quantities for VOC, benzene, ethylene, propylene, isoprene, 1,3-butadiene, sulfur dioxide, and nitrogen oxide were exceeded as a result of this event.